YUKAWA MATRICES FROM A SPONTANEOUSLY BROKEN ABELIAN SYMMETRY

We classify all the phenomenologically viable fermion mass matrices coming from a spontaneously broken abelian symmetry U(1)x, with one and two additional chiral fields of opposite charges X = +/- 1. We find that the non-trivial Kahler metric can fill zeroes of the fermion mass matrices up to phenomenologically interesting values. A general anomaly analysis shows that for one additional chiral field the only way to achieve anomaly cancellation is by use of the Green-Schwarz mechanism. For two additional fields with X = +/- 1 and negative charge differences in the lepton sector the anomalies can however be directly put to zero. This case gives a unique prediction for the ratio of the two Higgs scalars of MSSM, tg beta similar to m(l)/m(b) (sine theta(c))(2), where theta(c) is the Cabibbo angle.